Some voters will have a decision to make on Election Day, and it’s not just who to vote for — but which party’s primary to participate in.

Idaho is one of 13 states with partially closed primaries. Since 2011, each political party in Idaho can set its own rules on who can participate in its primary.

To view sample ballots for each primary in your area, visit VoteIdaho.gov. There are four sample ballots for this election: Republican, Democrat, Libertarian and Unaffiliated.

The Idaho Republican Party primary is closed. Only registered Republicans can participate in the GOP primary. The deadline to change party affiliation passed on March 13.

But unaffiliated voters can change their affiliation at the polls on Election Day and register as Republicans to participate in the primary, as explained by Joe Parris, public information officer for the Idaho Secretary of State’s Office.

“If you’re clean slate and you’re unaffiliated, you can pick whatever party you want and register at the polls that day,” he said.

In a Republican stronghold like Idaho, Parris said a lot of the outcomes are determined in the GOP primary.

“We know that a lot of voters, whether they’re Republicans or not in true practice, they do affiliate as Republicans, so they can be a part of that primary,” Parris said.

The Idaho Democratic Party is open. Any registered voter can participate in a Democratic primary in Idaho, even registered Republicans.

There’s no need to change party affiliation to vote in a Democratic primary.

Unaffiliated voters who wish to remain unaffiliated have a separate ballot, which mostly consists of state and local judges.

The ability to change affiliation opens back up the day after Election Day on VoteIdaho.gov.